Yes it will be fine. Much will depend on what OS you will run and in turn how you want to do storage. NAS drives might not be necessary if you going to use software defined storage. If in your budget consider a CPU with more cores for virtualization and docker.

Overall nothing wrong with that configuration. But if you really get into all the awesome stuff you can self host your two constraints are RAM and CPU cores.

If the USB port doesn’t provide enough power constantly it might have an influence. If you are on a desktop type computer use the ports on the back that are directly connected to the main board.

This is usually done by owner of the IP address block. If this is for a VPS or similar it will be your hosting provider. If you get a static IP from your internet service provider you will have to speak to them. Although depending on the policy of the provider this may be a business option only.